Complex Brick Systems is a multi-phased ongoing research projects that commenced prior to the PhD research of Defne Sunguroğlu Hensel and RCAT and in a variety of research contexts and schools and is now collected in the performance-oriented design research area of the OCEAN Design Research Association.

The research involves the development of various projects and products, including [i] the Nested Catenaries prototypes and pilotprojects, [ii] pre-stressed double curved brick systems without mortar, and related to this [iii] the development of special bricks, [iv] computational experiments with breaking symmetry of existing advanced brick systems to respond to local conditions.

NESTED CATENARIES _ 2010 - ongoing

Nested Catenaries is an ongoing research project that investigates the structural and multi-functional capacity of masonry catenary arches and vaults, which are demonstarted through a series of built prototypes and pilotprojects.

For their article on the Nested Catenary research Research Fellow Defne Sunguroglu Hensel and Adjunct Professor Guillem Baraut Bover win the prestigous Tsuboi Award in the category of the most meritorious paper published in the Journal of the IASS (International Association for Shell and Spatial Structures founded by Eduardo Torroja in 1959) for the year 2013. The Tsuboi Award honors the memory of Professor Yoshikatsu Tsuboi (Japan, 1907-1990), former President and Honorary Member of the IASS, and his outstanding contributions to structural and architectural design.

NESTED CATENARIES _ PHASE 01, OSLO, NORWAY, 2010

In October 2010, a series of events at AHO Oslo School of Architecture and Design focused on the topic of structural masonry exemplified by the innovative works ofEladio Dieste. (1) As part of these events the brick construction experiments workshop commenced with a line of inquiry based on the basic principles of the catenary arch derived through a form-finding method first utilized three dimensionally by Antoni Gaudi, the hanging chain model.

The brick construction experiments aimed at exploring some of the heretofore unexplored potentials of a catenary arch arrangements, focusing on the spatially organized network of interacting Catenaries. The aim was to accomplish an undulating wall made from nested catenaries. This research challenge formed the basis of a ten days intense brick construction experiments workshop run together with the master mason Øyvind Buset and nineteen master level students from the AHO Auxiliary Architectures Studio. Methodologically the research employed a combination of physical form-finding experiments with hanging chains, digital parametric and associative modelling, and 1:1 scale tests.

The form-finding team developed complex arrangements of hanging chain models in an iterative manner investigating the various configurations that the chain arrangements developed under their own self-weight. The experiments were carried out across different scales ranging from 1:1, 1:4 to 1:10 studying analogously the underlying geometric principles, the parametric definition and behaviour starting from a single chain towards more complex arrangement of chains that are point loaded as a result of a nested assembly.

The computation team worked on several tasks simultaneously. One area of investigation focused on the digital registration of the results gained from the physical form-finding experiments, using a mechanical Digitizer and employing photometric readings to extract empirical information. Two methods for computing nested chain behaviour were developed and investigated in parallel, which constitute [i] the development of an associative parametric set-up [ii] the implementation of the

Kangoroo physics engine to the Rhino Grasshopper set-up. (2) The findings from both the chain models and the 1:1 partial physical tests informed the development of the digital models with the aim to develop the design and construction drawings for the construction of the full-scale prototype.

The construction team built different configurations of catenary arrangements, conducted load tests and investigated different brick laying strategies with focus on the ‘key stones’ at the arch intersections, and developed practical information for carrying out the construction process. The construction of the full-scale prototype was conducted in house with low-tech tools available at the AHO workshop. The final prototype consisted of 950 bricks and covered a floor area of approx. 8000 x 2000 mm reaching 2500 mm high at its highest point.

(1) The Eladio Dieste - Advancing Architecture Through Material Systems InnovationExhibition and Symposium was organized by Michael Hensel, Defne Sunguroglu Hensel and Birger Sevaldson and sponsored by Byggutengrenser.no, Wienerberger, Weber and Einar Stange at the Oslo School of Architecture and Design, AHO during 08-22 October 2010.

(2) Grasshopper is a parametric modeling plug-in for Rhino, which is a NURBS-based 3-D modeling software. The physics engine Kangaroo for Grasshopper embeds relaxation script for digitally simulating the physics behind the hanging chain. Currently under development by Daniel Piker. See

Phase 02 of the Nested catenary project consitutes a prototype that served to establish the construction process for for phase 03. This phase extends the system from a set of nested catenary arches to nested catenary vaults.

The project was built as an extension to the cemetery of the Open City in Ritoque, Chile, and constitutes a masonry shell of interconnected sub-shells that are nested to form a vault between two cavity walls. It also involved a strategy of branching as a principle to span and to create nested spaces. The design was limited to twelve sub-shells in creating the overall shell articulating a volume of 162m³, each with synclastic surface geometry to retain the complexity of construction. The structural independence from symmetry and freedom from repetition due to the construction method allowed for a non-uniform spatial organization. The final structure is a nested catenaries shell, produced by spatially organized sub-shells with a thickness of 55mm. The span reaches to 7m in both directions with reaching a height of 3.3m. A total of 1000 bricks were used, which makes an overall weight of approx. 2800 kg including mortar. Thus far, it has survived several earthquakes of a magnitude above 6 on the Richter scale.